1. Field of the Invention
The present invention relates generally to a sense amplifier, and more particularly to utilizing the sense amplifier in order to select a suitable circuit that generates a voltage greater than or equal to a configurable reference voltage.
2. Description of the Related Art
Computing devices are widely used for performing tasks that involve storage and transmission of sensitive information. Moreover, with the rise of cybercrime and the increased interconnectivity between computing devices, via computer networks, a person can circumvent cybersecurity built to protect the computing devices and obtain unauthorized access to the sensitive information through the Internet. Therefore, it is important to provide increased protection of the sensitive information to prevent unauthorized access. However, protecting the sensitive information from unauthorized access can be challenging and expensive.
It is known to utilize integrated circuits to perform authentication in order to protect the sensitive information on the computing devices from unauthorized access. A single field-effect transistor comparison physically unclonable function circuit (SFC circuit) can generate a random output voltage signal that corresponds to a random data bit of “1” representing logic HIGH or “0” representing logic LOW, wherein the random data bit can be utilized to yield a random data bit sequence for purposes of authentication. Specifically, a series of SFC circuits can be operatively connected to generate random output voltage signals that can be combined to yield the random data bit sequence of ones and zeroes. The random data bit sequence can be utilized to generate a secret key for purposes of authentication. Moreover, the secret key generated can provide a high level of security around sensitive information on a computing device because a person trying to gain unauthorized access to the secret key must do so while the SFC circuits are powered on and operating, since the secret key is not stored in memory but instead is generated utilizing physical characteristics of the SFC circuit while in operation.
Furthermore, it is also known for a SFC circuit to generate a strong random output voltage signal (i.e., a magnitude greater than about 50 mV) or a weak random output voltage signal (i.e., a magnitude less than about 50 mV) at the output of the circuit. However, it is not desirable for the SFC circuit to generate a weak random output voltage signal, because the polarity of the weak random output voltage signal can vary based on operating temperature variation of the SFC circuit. If the polarity of the output voltage of a SFC circuit varies, then a random data bit sequence that is formed utilizing the SFC circuit, may have an error. An error in the random data bit sequence can result in generating a secret key that is not reliable. A secret key that is not reliable may result in a failure of an authentication process that utilizes the secret key and involves cryptographic operations, which can prevent a non-adversarial computing device from authenticating itself and accessing information when needed. Accordingly, it is desirable to select suitable SFC circuits that generate strong random output voltage signals that do not change polarity based on operating temperature variation of the SFC circuits and that can be utilized to generate a secret key.